Crews working for the state Department of Transportation have completed more than half of the tunneling for the new culvert that will carry Thunder Hills Creek underneath I-405 near Benson Road in Renton.

The existing culvert collapsed in last December’s rain storm. This work is occurring between 7 a.m. and 4 p.m. on weekdays, and should continue until the end of July. Drivers should expect intermittent weekday single lane closures from 9 a.m. to 2 p.m. on Benson Road.

Crews have completed work to fill in and seal the old culvert.

Major work is also coming up rapidly on Interstate 405 later this summer.

To make room for more southbound I-405 lanes in south Bellevue, crews will remove the Wilburton Tunnel in August.

To do the work crews will close southbound I-405 around the clock from Southeast Eighth Street to I-90 during three weekends: Aug. 8 –11; Aug. 15-18; and Aug. 22 –25.

Also from Aug. 8 – 11, crews in Renton and Tukwila will close southbound lanes on I-405 and the southbound SR 167 to southbound I-405 ramp to build the I-405 bridge over Oakesdale Avenue Southwest.